1. Field of Invention
The present invention relates to a display driving technology of a panel display apparatus, more specifically, to a source driver of a panel display apparatus. This source driver can optimize the operation voltage with the operation speed.
2. Description of Related Art
Due to the great advancement and development in video display technology in recent a few years, a large portion of the conventional Cathode Ray Tube (CRT) has been substituted with the so-called panel display. The common panel display is thin-film transistor liquid crystal display (TFT-LCD). In addition, the LCD panel display or plasma panel display are becoming more and more popular.
The display portion of panel display includes pixel array which usually is determinant matrix. And the pixels are controlled by the driver. The corresponding pixels are driven according to the video data.
FIG. 1 illustrates a circuit block diagram of the source driver of conventional LCD display. LCD display drives pixels using a source driver and a gate driver. Color correction data will be input to the source driver to correct the color of display. As shown in the figure, the source driver usually includes a shift register, a line latch, a level shifter, a digital to analog converter (DAC), output buffer, a signal receiver and a data register. Wherein, the DAC receives Gamma voltage VGMA1-VBGMA14 of Gamma color connection curve which is input in parallel. Signal receiver receives input signals, for example receives signals corresponding to RSDS. In addition, the output buffer outputs several signals Y1, Y2, . . . to drive the display of pixels. Since the conventional source driver shown in FIG. 1 is a conventional technology which is known by those who are skilled in the field, therefore it is not described in detail herein.
And for source driver, the input of which can include Gamma voltage, data signal, control signal, carry in, analog voltage, digital voltage and clock, etc. As for output, it also includes a carry out. Since these input and output signals and source driver operation can be know by those who are generally skilled in the field, therefore it is not described in detail herein.
In addition, for the conventional panel display apparatus, for example TFT LCD, the voltage supplied to the logic system usually is 3.0V˜3.6V, and 3.3V is relatively a common setting. In this situation, the logic core circuit of the source driver and the gate driver operates at 3.0V˜3.6V or 3.3V. For the conventional source driver, all of the internal operation is at the same logic operation voltage which is the same as that of the system. When the system sets a logic voltage, the speed and power within the driver usually are not at an optimized value, and can not be adjusted dynamically. The speed within the driver for example refers to gate delay time reciprocal, and the power refers to the operation power provided to the logic circuit.
In addition, if the power consumption of the panel display is too large, for some of the portable electronic apparatus with panel display, the duration of the batteries may be reduced, and it is impossible to achieve an optimized operating speed.